This invention relates to inner space target detection where a sound detection system of sonar is positioned in an inner space vehicle or at an inner space station.
In prior known sonar devices of this type a plurality of sonar microphones are positioned about the vehicle or station such as in a circular configuration of sonar microphones arranged to listen through 360.degree. which microphones had to be switched in a desirable way to provide bearing of the target in the inner space. The prior known switching device was a mechanical rotary switch utilizing a plurality of brushes on slip ring and commutator style contacts to provide the desired combination of switch arrangement to connect the sonar microphones in the proper combination to the correct taps of delay lines to form a beam or beams at this bearing. The mechanical switching arrangement of this known type is most successful in operation but its operation is limited to a few hours since the mechanical switch contacts deteriorate rapidly and require frequent cleaning operations which shut down the equipment during these cleaning operations. Accordingly, it is desirable to eliminate such mechanical switching means since cleaning at intervals of time is inherent in such switches and it is desirable to mechanize such a switching system with non-mechanical or electronic, preferably solid state switching arrangements. Additionally, the accuracy of the mechanical switches is dependent on and limited by the mechanical dimensions and their stability with time.